Access to Shared Frameworks

When J2EE applications and modules use shared framework classes (such
as utility classes
and libraries) the classes
can be put in the path for the System Classloader or the Common Classloader
rather than in an application or module. If you assemble a large, shared library
into every module that uses it, the result is a huge file that takes too long
to register with the server. In addition, several versions of the same class
could exist in different classloaders, which is a waste of resources. For
more information, see Circumventing Classloader Isolation.